how to clear cache on emulator.
I don't use an emulator so I don't know if you can do this, but to get to the phone commands to wipe cache and Dalvik Cache, I booted into recovery (a custom recovery in my case, AmonRa - I don't think you can do this with a stock recovery) using the ROM Toolbox app. If you don't have that app, this is another way to boot into a custom recovery (your phone/emulator must be rooted):
1. Turn on USB debugging on phone.
2. Turn off Fastboot on phone.
3. Connect phone to PC in "Charge mode".
4. From PC (you must have adb and fastboot tools installed on PC), enter "adb reboot bootloader".
5. When you get the HBOOT screen on the phone, select FASTBOOT. Screen should display "FASTBOOT USB".
6. On your PC enter "fastboot boot <recovery>.img" where "recovery" is the name of a custom recovery (such as AmonRa) in the same Windows folder.
7. Once the custom recovery is booted, the commands to wipe cache and Dalvik Cache should be on one of its menus.